GOALI: Optical Differentiation Wavefront Sensing for High-Dynamic-Range High-Sensitivity Freeform Metrology

Rochester Institute Of Tech, Rochester NY

Investigators

Abstract

Freeform optics are optical components having no rotational symmetry, allowing for high-performance optical systems with reduced cost, size, weight and assembly complexity which are now used in applications such as head-worn displays for augmented reality, automotive lighting, astronomical telescopes, and projection systems. Freeform optics present significant manufacturing and metrology challenges, and push most commercially available wavefront diagnostics to their fundamental limits. The PI will investigate and demonstrate a new type of wavefront sensor, the optical differentiation wavefront sensor, which will improve the fundamental understanding and promote technological innovation of wavefront metrology for the measurement of freeform optics. Successful demonstration and commercialization of the optical differentiation wavefront sensor, possibly in combination with a coordinate-measuring machine, will provide a competitive advantage to American optical manufacturers that produce metrology equipment and manufacture freeform optical components. This wavefront-sensing technology can be applied to other fields such as laser engineering, astronomy, and biomedical imaging, all of which improve national science, technology, defense, healthcare, and economic growth. The impact of this GOALI proposal on inclusion of women will be transformative through the strategic collaboration with WiSTEE Connect, an organization that the PI has founded to improve the leadership, career opportunity and mentorship for women in science, technology, engineering, and entrepreneurship. The project will enhance the involved undergraduate and graduate students research experience in the PI's multidisciplinary laboratory. It will enable student interactions with industrial mentors and promote entrepreneurial career paths. The research objective of this GOALI proposal is to demonstrate a novel optical differentiation wavefront sensor and investigate its capability for high-accuracy and high-precision freeform metrology with decoupled dynamic range and sensitivity. The potential to achieve simultaneous high-dynamic-range and high-accuracy through combination with a commercial non-contact coordinate-measuring machine will also be investigated. The investigation will be performed via the combination of simulations using a complete model of the wavefront sensor and laboratory demonstrations of various configurations of the sensor with application to freeform optical components. The PI will investigate the ability of an optical differentiation wavefront sensor relying on binary pixelated filters to measure wavefront slopes and achieve decoupled dynamic range and sensitivity, high-accuracy, and high-dynamic-range wavefront measurements of freeform surfaces. She will create models of the wavefront sensor and filters to investigate the performance impact of design parameters of the optical system and filters. Novel methods for improving the performance, e.g. aperture stitching to increase the measurable aperture size and spatial dithering algorithms for designing the binary pixelated filters, will be evaluated. Optimal configurations of the optical differentiation wavefront sensor appropriate for different classes of freeform optical components will be identified and tested in a laboratory environment by characterizing test optical freeform components. The synergetic combination of an optical differentiation wavefront sensor with a commercial coordinate-measuring machine, with the potential for unmatched performance in terms of dynamic range and accuracy, will be studied via modeling and collaboration with the industrial co-PI. The novel realizations of the optical differentiation wavefront sensor will advance the fundamental understanding of this technology for characterizing freeform optics and elucidate its potential advantages over other approaches such as interferometry, deflectometry, Shack-Hartmann sensors, and coordinate measuring machines. The proposed research will also advance the technological capability of freeform metrology and manufacturing.